The first duo album by John Surman and Jack DeJohnette in more than 20 years - since 1981's 'Amazing Adventures of Simon Simon' - is an exultant, highly atmospheric disc recorded live at the jazz festivals of Berlin and Tampere. Surman and DeJohnette play totally improvised music that sounds pre-composed. Of the pieces on 'Invisible Nature', only one has a prearranged harmonic structure: the rest of the music is simply pulled out of the ether, and takes many forms. From the long almost ambient introductory 'Mysterium' to the free blues of 'Outback Spirits' to the Indian colours of 'Ganges Groove', this is improvisation of great variety. Long-time followers of Surman will be glad to hear him wailing joyously once more, over DeJohnette's propulsive drums. With additional use of electronics, the duo often sound like a larger band. DeJohnette's electronic percussion allows him to add a bass line from time to time, or to simulate sounds of congas, tabla and tympani. Surman's synthesizers, meanwhile, add spaciousness and depth to the instrumental texture.